All programmers are optimists -- Frederick P. Brooks, Jr.
First of all, thank you for your interest in the Postfix project.
What is Postfix? It is Wietse Venema's attempt to provide an alternative to the widely-used Sendmail program. Sendmail is responsible for an estimated 70% of all e-mail delivered on the Internet. With an estimated 100 million users, that's billions of messages daily. A stunning number.
Postfix attempts to be fast, easy to administer, and secure, while at the same time being sendmail compatible enough to not upset existing users.